apache/iceberg · error · UnsupportedOperationException

Unknown field ordinal:

Error message

Unknown field ordinal: 

What it means

V2Metadata.ManifestFileWrapper.get(pos) maps ordinals 0-14 to the V2 manifest-list schema (including partitions at 13 and key_metadata at 14). An out-of-range ordinal has no field and throws UnsupportedOperationException with the position, indicating the caller's struct shape does not match the V2 manifest schema.

Source

Thrown at core/src/main/java/org/apache/iceberg/V2Metadata.java:145

          return wrapped.snapshotId();
        case 7:
          return wrapped.addedFilesCount();
        case 8:
          return wrapped.existingFilesCount();
        case 9:
          return wrapped.deletedFilesCount();
        case 10:
          return wrapped.addedRowsCount();
        case 11:
          return wrapped.existingRowsCount();
        case 12:
          return wrapped.deletedRowsCount();
        case 13:
          return wrapped.partitions();
        case 14:
          return wrapped.keyMetadata();
        default:
          throw new UnsupportedOperationException("Unknown field ordinal: " + pos);
      }
    }

    @Override
    public String path() {
      return wrapped.path();
    }

    @Override
    public long length() {
      return wrapped.length();
    }

    @Override
    public int partitionSpecId() {
      return wrapped.partitionSpecId();
    }

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Bound access by size() (14 for V2 manifest files) rather than hardcoded counts
2. Verify pos maps to a MANIFEST_LIST_SCHEMA column before calling get
3. Ensure V1 code paths use V1Metadata wrappers and V2 use V2Metadata wrappers

Example fix

// before
Object v = wrapper.get(15);
// after
if (pos >= 0 && pos < wrapper.size()) { Object v = wrapper.get(pos); }

if (pos < 0 || pos >= MANIFEST_LIST_SCHEMA.columns().size()) { throw new IllegalArgumentException("ordinal out of range for V2 manifest list schema"); }

boolean validV2ManifestPos(int pos) { return pos >= 0 && pos < MANIFEST_LIST_SCHEMA.columns().size(); }

try { return wrapper.get(pos); } catch (UnsupportedOperationException e) { LOG.warn("bad ordinal {} for V2 manifest wrapper", pos); return null; }

When it happens

Trigger: Calling get(pos) with pos < 0 or pos > 14 on a V2Metadata.ManifestFileWrapper, often from generic iteration code bounded by a V1 schema size or a wrong constant.

Common situations: Mixed-version code paths reading V1-sized structs against V2 wrappers; hardcoded indices that predate the partitions/key_metadata columns; reflection-based readers with stale schemas.

Related errors

• Unknown field ordinal:
• Field + name + not found in source schema
• Cannot parse type string to primitive: + typeString
• Invalid default value for %s: %s (must be null)
• Unknown field ordinal: ${basePos}

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/b81dcfbb61afd38f. Report an issue: GitHub.